Social and psychological factors which may be important in putting people at risk for episodes of major depression are studies. The factors are remote and recent life events (for example, recent losses); personal dispositions (for example, external locus of control); situational contexts (for example, absence of social supports); and social positions (for example, being female). The main aims are to determine the relative importance of these factors and their specificity to major depressive disorder. The research involves 100 treated persons with major depression, 25 to 50 untreated persons with major depression, 100 persons with schizophrenia or schizophrenia like disorders, 60 to 75 persons with nonspecific distress, and 425 well persons from the New York City population. The research interview emphasizes the life events section of the Psychiatric Epidemiology Research Interview.